Comment 1: Page 22, bullet (3)(i) — A statement is made indicating the inclusion of emission

reductions “...not yet finalized but likely to achieve additional reductions...” in the “on-the

way/on-the-books” (OTW/OTB) emission inventories. Please address the uncertainty of

reasonable progress goals and modeled visibility progress considering the lack of enforceability

of emission reductions.

Response: The draft SIP has been revised to clarify that DE is not relying on any control

measure that is not yet finalized. The draft SIP now clearly states that Delaware’s 2018

emissions projections are based only on adopted and finalized control measures, and are less than

MANE-VU modeled OTB/OTW emissions. As such, there is no uncertainty regarding the lackof enforceability of emission reductions in the DE SIP.

Comment 2: Page 23, second paragraph -The first sentence refers to the visibility SIP as an

“attainment” demonstration. The State only has to demonstrate progress towards the Nation’s

visibility goals. This is not an attainment demonstration. Please consider rewording this section.

Response: The draft SIP has been reworded as suggested.Comment 3: Comment #1 applies here as well “Page 22, bullet (3)(i) — A statement is made

indicating the inclusion of emission reductions “. . . not yet finalized but likely to achieve

additional reductions...” in the “on-the-way/on-the-books” (OTW/OTB,) emission inventories.

Please address the uncertainty of reasonable progress goals and modeled visibility progress

considering the lack ofenforceability ofemission reductions.”Response: The draft SIP language has been clarified. See response to Comment 1 above.

Comment 4: Comment #2 applies here as well “Page 23, second paragraph — The first

sentence refers to the visibility SIP as an “attainment” demonstration. The State only has to

demonstrate progress towards the Nation ‘s visibility goals. This is not an attainmentdemonstration. Please consider rewording this section.”

Response: The draft SIP has been reworded as suggested.Comment 5: Page 25, first paragraph, second to last sentence — It is suggested that aircraft,

railroad, and commercial marine emissions are grown and controlled into the future consistent

with Clean Air Interstate Rule (CAIR) analysis. Please explain how this was done and whether

these controls are enforceable.

Response: The draft SIP has been clarified to state that Aircraft, railroad, and commercial
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inventories relate to the SIP. It is not clear why MV 2002 v.2 is referenced considering MV2002

v.3 is identified as the final 2002 inventory on page 37.Response: Delaware believes that emissions inventory trend analysis relates to this SIP as it is avaluable tool in emissions characterization and for evaluating progress in air pollution control ona per-pollutant basis. For example, this comparison of inventories clearly show that sulfurdioxide our largest emitted visibility impairing pollutant. All references to MV2002 v.2 have

been updated to MC2002 v.3 as suggested.

Comment 7: Page 28, first paragraph — second to last sentence — indicates that “Recent efforts

to reduce manmade organic carbon emission have been undertaken.. . .“ Organic Carbon (OC) is

identified as the second most significant contributor in MANE-VU. Can you expand yourdiscussion on what efforts were made to control OC? Please relate this to the wood stovediscussion on page 86.

Response: Organic carbon (OC) compounds are a subset of volatile organic compounds

(VOCs.) Delaware has adopted, implemented, and enforced numerous (VOC) control measures

over the past 40 years, to include measures that cover thirty eight (38) source categories under

DE Regulation 1124. These measures are projected to reduce 2018 emissions by 12,306 tons per

year (a 32% decrease) from 2002 levels. Tables 7-4 and 7-5 present this information. Based onthis comment changes were made to the narrative to expand discussion on VOC/OC controls.

VOC Regulations which are adopted and in effect are now listed in a new Appendix 7-6 of the

proposed SIP. Regarding wood stoves, the draft SIP has been revised to note that residential

woodstoves are controlled through federal New Source Performance Standards, 40 C.F.R. Part60 Subpart AAA.Comment 8: Page 71 — Similar to comments on page 22, a statement indicates that the 2018

“beyond on the way” (BOTW) emissions inventory includes controls that are “not yet finalized

but are likely.” This statement should be discussed if the State relied on this inventory forplanning purposes. Please summarize how this inventory was used by the State and consider

additional discussion if necessary.

Response: Delaware has revised the draft SIP to specifically reflect Delaware’s emissionsinventory based only on finalized and enforceable control measures. The draft SIP now clearly

shows that current Delaware/federal rules and regulations demonstrate that Delaware meets its

fair share of the reasonable progress goals. Section 11 discusses these measures in detail.Comment 9: The BART determination for Indian River, LLC, utilized 98th percentile (8th high

per year) modeling results in conjunction with MANE-VU generated CALMET fields. These

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Appendix W guidance would be considered.

The FWS has a strong concern that MANE-VU generated CALMET data sets are not ofsufficient quantity or quality to address BART exemption or determination expectations.MANE-VU did not intend this modeling for exemption purpose and voluntarily used lS high

results (and possibly 20% best background values) for all of its assessments. The FWS was

satisfied with MANE-VU’s use of conservative assumptions to satisfy modeling concerns.

However, elimination of these conservative measures negates our acceptance of the MANE-VU

modeling approach.

If the State intends to use 8th high results from the CALMET/CALPUFF modeling system, the

FWS expects modeling of sufficient quantity and quality to meet the guidance provided for

BART exemption standards.

Response: Delaware agrees with this comment, and the draft SIP has been revised to reflect

Indian River’s BART analysis based on the new assumption of 1st highest day (i.e., the most

conservative approach). An Addendum to NRG-Indian River’s BART analysis has been added

to Appendix 8. The results of the re-analysis show that proper operation of the existing

electrostatic precipitator constitutes BART controls for particulate matter.

Comment 10: Three facilities located in Delaware were determined to be BART-eligible andsubmitted BART determinations. The three facilities are the City of Dover — McKee Run

Generating Station, Indian River Operations, LLC — Indian River Generating Station andConectiv Delmarva Generation, Inc. — Edge Moor Power Plant. All three are electric generationunits (EGUs) and since Delaware is affected by the Clean Air Interstate Rule (CAIR), the

DNREC is only required to perform a BART determination for PM10.Additional source-specific

BART recommendations are as follows:

a. Indian River Operations, LLC — Indian River Generating Station and Conectiv

Delmarva Generation, Inc. — Edge Moor Power Plant

Both ofthese facilities declared that the PM10 control equipment already in place wasdeemed to be state-of-the-art, best available control technology or maximum achievable

control technology. As such, these facilities did not need to finish the cost analysis

portion of a BART determination, but each went on to demonstrate excessive cost per ton

and cost per deciview of alternative controls. If DNREC agrees with the companies’

conclusions, it should make an affirmative statement in the Regional Haze SIP documentthat the control technology currently deployed is considered to be BART.

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fuel oil to comply with Delaware’s Multi-Point regulation for SO2and that this action is

considered a control option for PM10.Section 5, item 4 states that since Boiler 3 will be

required under Delaware’s Multi-Point regulation for SO2to meet the 0.5% sulfur inresidual fuel requirement, “Therefore, the consideration ofBART controls for Boiler 3

should be compared above and beyond the control level expected from compliance with

the fuel sulfur specification of Delaware’s Multi-Pollutant regulations. It should be noted

that a BART determination is required to be performed using a ‘pre-control’ baseline,rather than a baseline assumption that includes a yet-to-be-installed improved sulfur

content fuel employed for purposes of another regulatory program.

A wet electrostatic precipitator (ESP) is considered as a BART alternative, but cost

analysis of the alternative is not performed. It is stated at the bottom of page 3-8 that the

wet ESP alternative will not be analyzed since it offers a similar or lesser level of PM10

control than those already identified in the fuel switching options, but when all fuelswitching alternatives are later deemed to be too expensive for BART, the wet ESP is

never analyzed separately. The cost of a wet ESP should be analyzed as a BART

alternative.

Even though a 0.5% sulfur in residual fuel requirement was deemed too expensive to beconsidered BART, it will nevertheless be deployed under Delaware’s Multi-Point

regulation for SO2. In a ‘backdoor’ fashion this will result in some visibility

improvement, even though it is not technically a BART control. We suggest that DE

document this control within the BART discussion of the SIP narrative as well.

Response: Delaware agrees with these comments, and has updated Section 8 -BART revisions,

and Appendix 8-2 ofthe proposed SIP accordingly.

Comment 11: Page 8, second to last paragraph; Page 10, Table 1-2; and, Page 54, third

paragraph — In these sections, DE communicates that the State is a contributor to visibility

impacts at Shenandoah National Park and the Dolly Sods Wilderness Area. Yet, the VISTASassessment concludes that DE does not contribute to visibility impacts at these Class I areas.The State should consider the VISTAS assessment which does not identify DE as a significant

contributor to these areas. Because Virginia (VA) and West Virginia (WV) are the States setting

the reasonable progress goals for these Class I areas, it is consistent to address your attribution asdescribed by VISTAS. Please evaluate and summarize the Area of Influence (AOl) information

produced by VISTAS and identified by VA and WV. If DE continues to consider its emissions

as contributing, it should document consultation between itself and both VA and WV.

Response: Delaware agrees with this comment, and with the analysis of VA and WV that

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have been deleted from the proposed SIP. Because of this a map including VA and WV is not

relevant and has not been added to the proposed SIP.

Comment 13: Page 59, first paragraph — The description of Q/d (emissions/distance) data

multiplied by a “prevailing wind factor” should be renamed when displaying data identified in

following figures. Q/d is an established ratio for BART and RH use. If modified with an

additional modifying factor, a new name representing the unit label should be considered to

avoid confusion.Response: Since REMSAD modeling of annual average percent sulfate was the chosen

methodology in determining contributions to Class I areas, the proposed SIP has been revised toreflect that Q/d multiplied by the prevailing wind factor is not relevant to this proposed SIP. Allreferences to prevailing winds have been deleted.

Comment 14: Page 68, fourth paragraph — A small reference is offered suggesting MANE-VUair quality model performance meets EPA guidance. Model performance is a critical element toestablish when using a non-guideline model for air quality purposes. The Regional Planning

Organization (RPO) and State rely on model analysis and subsequent predictions as the primary

basis for demonstrating progress. The August, 2006, NPS/FWS letter to the States identified

model performance evaluation as a priority element. Please provide sufficient discussion andconclusions at a regional and local level regarding model performance in the main body of the

SIP.

Response: We agree with this comment and have added a discussion regarding model

performance in the proposed SIP (see new Section 9.6)

Comment 15: Page 78, Section 10.4 — The reference to 40 CFR Section 51.308(d)(3)(v) isincorrect. The requirement for each State to evaluate reasonable progress is stated in Statute

169A (b)(2). References in 51.308 for non-Class I States to evaluate reasonable progress

controls using the 4 factors is indirectly implied. We encourage the State to keep the statement

to review reasonable progress in the SIP. Please consider referencing the Statute.

Response: Delaware agrees that the reference to 40 CFR Section 51.308(d)(3)(v) isincorrect. The draft SIP has been changed to reference that “40 CFR Section 51.308(d)(1), was

promulgated under the authority ofsection 169A(b)(2) ofthe federal Clean Air Act and requires

Class Istates...”

Comment 16: Page 79, following bullets — Please summarize how DE will adopt and apply the

previous MANE-VU bulleted statements in this section.

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Comment 17: Page 86, second to last paragraph — Wood smoke is considered a negligible or

low contributor to visibility impairment at the nearby Class I areas because it accounts to “less

than 10%.” It is not clear what this “10%” means. In prior discussion, MANE-VU determinedthat all States with contribution greater than 2% of sulfur on the 20% worst visibility days were

significant. Please address what 10% is related to (i.e., 20% best or worst visibility days? All

data? Etc...) and why such a high apportionment is necessary when dealing with the second mostapportioned pollutant.

Response: Based on this comment Delaware has significantly revised this section. Emissioninventories and source apportionment studies in Delaware do not show woodsmoke a significant

source. All references to “less than 10%” have been deleted, since that did not reflect Delaware,

or Brigantine source apportionment of wood smoke..

Comment 18: Page 8 8-90 — Figures with glide slope information are too coarse to read. From

what we can see, the charts indicate how the MANE-VU models predict visibility progress at the

affected Class I areas. There is too little information describing what the figures are intended to

represent and how to read them. Are these charts presenting direct model results or relativeresponse factors? Please describe this important data with a wide, non-technical audience in

mind.Response: A new figure showing glide slope information for Brigantine has been added to the

proposed SIP. This figure was expanded in size to increase resolution and address the

“coarseness”. In addition, subsection 9.9 has been revised to describe what the figures are

intended to represent and how to read them.Comment 19: PSD permit review should be discussed as to how this program will benefit

visibility. Please make direct statements on how DE has committed to review PSD actions in a

way that supports progress goals in the regional haze program.

Response: Section 3 of Delaware’s Regulation 1125 contains Delaware’s PSD (Prevention of

Significant Deterioration) program, and requires Delaware to review PSD actions with

consideration of visibility impacts. It is designed to prevent adding new (or modified) source

emissions increases without determining ifthey will impact air quality or Class I areas adversely.The proposed SIP has been revised to reflect this.

Comment 20: Page 87 — The State provides a good description on prescribed burning. Can you

discuss whether visibility impacts at Class I areas are considered when issuing a burningauthorization? If not, would the State consider adding this provision to make a more directconnection between visibility protection and prescribed burning activities?

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(NESCAUM) is identified for 2008. Significant issues have been raised regarding these final

runs. These runs seem to contradict assumptions and possibly go against known controls in other

States. Please add a significant discussion on these differences in regards to emission inventory

assumptions, uncertainty, and differences from both MANE-VU and VISTAS results.

Response: Delaware has revised the proposed SIP to clarify that Delaware does not

significantly impact any of VISTAS Class I areas (see response to comment 11 above). All nonBrigantine Class I area references have been deleted. Because of those deletions/revisions, the

comment is no longer applicable to this proposed SIP.

Comment 22: A detailed discussion of emissionlmodeling uncertainty and the conflict with the

VISTAS modeling is needed. The final modeling conducted by MANE-VU is not enough forDE. Inclusion of VISTAS modeling, performance, and AOl is important to the impacts since DEcontributes to Class I areas in WV. The latest “Best and Final” MANE-VU modeling runs

indicate that a Class I area in WV may not be meeting the URP. Delaware must explain thisdiscrepancy and could discuss it in the context that VISTAS concluded that the URP would be

met.

Response: Delaware has revised the proposed SIP to clarify that Delaware does not

significantly impact any of VISTAS Class I areas. See response to comment 21 above.Comment 23: Section 12 of the Draft SIP discusses the options for action following the fiveyear review. However, the document does not provide any criteria that DE will use in evaluating

the five-year progress report to decide which of the listed actions would be indicated. Please

include discussion of the anticipated criteria that DE will use to both evaluate the progress at the

five-year review and to select the course of action that will be taken based upon that review.

Response: Section 12 of the draft SIP refers to a future SIP submittal, to be submitted to EPA

five (5) years after this SIP. Delaware does not agree that it is necessary to include criteria to be

used in a future SIP within this SIP.

Comment 24: Page 16, third paragraph — The Fish & Wildlife Service and National ParkService received the Delaware SIP on April 28, 2008. Please adjust the date indicating the start

of DFs FLM draft SIP review.Response: April 28, 2008 is the date in the draft SIP.

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